Method, computer program product and processing circuitry for pre-processing visualizable data

ABSTRACT

Visualizable data are obtained that represent a scene with at least one object. The visualizable data describe the scene as seen from a position. First and second measures are determined, which represent extensions of one of the objects in a smallest and a largest dimension respectively. An object aspect ratio is calculated that represents a relationship between the first and second measures. Based on the object aspect ratio, a selection margin is assigned to the object. The selection margin designates a zone outside of the object within which zone the object is validly selectable for manipulation in addition to an area of the object shown towards a view thereof as seen from the position. Thus, it is made easier to manipulatable the visualizable data in response to user input, for instance in the form of gaze-based selection commands.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims benefit to Swedish patent application No.2030113-1, filed Mar. 31, 2020, entitled “Method, Computer ProgramProduct and Processing Circuitry for Pre-Processing Visualizable Data”,and is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The invention relates generally to manipulation of visualizable data ona user-friendly format. In particular, the instant invention concerns amethod for pre-processing visualizable data to be manipulatable inresponse to user input, and a processing circuitry configured toimplement such a method. The invention also relates to a computerprogram product and a non-volatile data carrier.

BACKGROUND

Depending on the conditions, it can be a relatively complex task todetermine which object in a group of potentially selectable objects thata subject intends to select, or by other means manipulate. Especially,this may be true if the selection is made based on the subject's gaze.However, similar problems may also arise in scenarios where theselection is made by other input means, for example via ahand-controlled cursor or on a touchscreen. Namely, the intended objectmay be obscured by other objects, by the subject's own finger and/or theintended object may be oriented relative to the subject in such a mannerthat the object shows a very small surface towards the subject'sviewpoint. Of course, the selection process can be further complicatedby the fact that the composition of the scene containing the object tobe selected varies over time so that it becomes motorically difficultfor the subject to indicate the intended object correctly.

U.S. Pat. No. 9,829,973 describes a solution for identifying aninteraction element from one or more interaction elements present in auser interface. Gaze information is received from an eye trackingsystem; the likelihood is determined that an interaction element is thesubject of the gaze information from the eye tracking system; and aninteraction element is identified from the one or more interactionelements based on said likelihood determination.

WO 2016/193394 discloses a method for determining if a user's gaze isdirected in the direction of a zone of interest in a 3D scene. Themethod involves providing a 3D scene containing a zone of interest;associating a property with the zone of interest and creating a bitmaprepresenting the location of the zone of interest in a projected view ofthe 3D scene. Here, each pixel of the bitmap to which the zone ofinterest is projected stores the property of the zone of interest. Thedirection of the user's gaze is detected, and the bitmap is used todetermine if the detected user's gaze is directed in the direction ofthe zone of interest.

The above documents exemplify how users may interact efficiently withdigital visual elements in a gaze-based manner. However, still, problemsremain to be solved, especially when pinpointing objects that arechallenging to select due to their size, shape and/or dimensionalrelationship with any neighboring objects.

SUMMARY

It is therefore an object of the present invention to offer an improvedsolution for facilitating user interaction with visualizable data, forexample in the form of 3D images, or computer graphics.

According to one aspect of the invention, this object is achieved by amethod performed in at least one processor for pre-processingvisualizable data to be manipulatable in response to user input. Themethod involves obtaining visualizable data representing a sceneincluding at least one object. Here, the visualizable data describes thescene as seen from a position, for instance represented by a virtualcamera position or the location from which an image of the scene wasshot. First and second measures are determined representing extensionsof the object in a smallest and larges dimension respectively as seenfrom the position. An object aspect ratio is calculated representing arelationship between the first and second measures. Based on the objectaspect ratio, a selection margin is assigned to the object. Theselection margin designates a zone outside of the object within whichzone the object is validly selectable for manipulation in addition to anarea of the object shown towards a view thereof as seen from theposition in question.

This method is advantageous because it facilitates user interaction withobjects in a scene regardless of which selection technique that isapplied. However, the method is especially beneficial for gaze-basedselection and where the object to be selected has a relatively largeaspect ratio, i.e. a substantial difference between its largest andsmallest dimensions.

According to one embodiment of this aspect of the invention, thedetermining of the first and second measures involves encapsulating theobject in a rectilinear box covering the object in the view thereof asseen from the position. The first measure is set equal to a shortestside of the rectilinear box, and the second measure is set equal to alongest side of the rectilinear box.

Determining the first and second measures may involve obtaining positiondata describing a respective position of each of at least four cornersof a cuboid encapsulating the object. More precisely, the cornersinclude a base corner and three corners of the cuboid, which threecorners are located on a respective edge directly connected to the basecorner. Based on the respective position of each of the at least fourcorners, each of the corners being visible from the position isprojected onto a plane that is orthogonal to a direction of the view.Thus, a planar projection of the cuboid is obtained. Thereafter, alargest diagonal in the planar projection is determined. A cross-measureperpendicular to the largest diagonal is also determined, whichcross-measure extends between two opposing sides of the planarprojection. The first measure is assigned equal to the cross-measure,and the second measure is assigned equal to the largest diagonal. Thisstrategy provides a relevant selection margin to objects of all shapesand dimensions.

According to another embodiment of this aspect of the invention, theselection margin is assigned such that the zone has a non-zero extensionoutside of the object along at least one buffer side of the object. Thismeans that the selection margin may extend from less than all sides ofthe object shown towards said position.

Preferably, each of the at least one buffer side is located on a side ofthe object, which side extends in a general direction of the largestdimension of the object. In other words, if the object has a generaloblong shape, the at least one buffer side is preferably located alongone or more of the object's longer sides. Thereby, it is rendered easierfor a user to select the object because also a near miss, however withinthe margin of a buffer side, results in a valid selection. It is lessrelevant to provide such a selection margin along the object's shortersides, since in this dimension the object itself is relatively wide, andtherefore easier to hit with a selection input.

Specifically, according to another embodiment of this aspect of theinvention, the selection margin is therefore assigned such that the zonehas a wider extension from a side extending in a general direction ofthe largest dimension of the object than an extension of the zone from aside extending in a general direction of the shortest dimension of theobject as seen from the position.

According to yet another embodiment of this aspect of the invention, theselection margin is defined based on a threshold angle outside of atleast one edge of the object in the view thereof as seen from theposition. This is advantageous because thereby, for a given view angletowards the scene, a linear relationship is maintained between anobject's aspect ratio and the selection margin assigned to the object ifthe distance between the position and the scene is varied. Consequently,the behavior becomes predictable.

According to still another embodiment of this aspect of the invention,the selection margin is assigned such that an extension of the zone inat least one direction outside of the object depends on the objectaspect ratio according to the expression: E=KR^(−x), where E is theextension of the zone in the at least one direction, K is a constantlarger than zero, R is the object aspect ratio, smaller than or equal toone (i.e. the smallest dimension compared to the largest ditto), and xis a constant larger than or equal to one. The expression specifies thata relatively large difference between the object's smallest and largestdimensions results in a comparatively wide extension of the zone in theat least one direction outside of the object, and vice versa. Themagnitude of this effect can be adjusted by selecting the constants Kand x to different values.

According a further embodiment of this aspect of the invention, the userinput is produced based on gaze data registered for a subject regardinga display on which the scene is presented as seen from the position,and/or tactile input registered on a display presenting the scene asseen from the position. Thereby, the user interaction can be effected ina reliable and consistent manner.

According to another aspect of the invention, the object is achieved bya computer program product loadable into a non-volatile data carrierbeing communicatively connected to at least one processor. The computerprogram product contains software configured to, when the computerprogram product is run on the at least one processing circuitry, causethe at least one processing circuitry to obtain visualizable datarepresenting a scene including at least one object. The visualizabledata describe the scene as seen from a position, for instancerepresented by a virtual camera position or the location from which animage of the scene was shot. The software is configured to determine afirst measure representing an extension of the object in a smallestdimension, and a second measure representing an extension of the objectin a largest dimension as seen from the position. Additionally, thesoftware is configured to calculate an object aspect ratio representinga relationship between the first and second measures, and, based on theobject aspect ratio, assign a selection margin to the object. Theselection margin designates a zone outside of the object within whichzone the object is validly selectable for manipulation in addition to anarea of the object shown towards a view thereof as seen from theposition. The advantages of this computer program product andnon-volatile data carrier are apparent from the discussion above withreference to the proposed method.

According to yet another aspect of the invention, the above object isachieved by a processing circuitry for pre-processing visualizable datato be manipulatable in response to user input, which processingcircuitry is configured to implement the above-described method. Theadvantages of this processing circuit are apparent from the discussionabove with reference to the proposed method.

According to yet another aspect of the invention, the above object isachieved by a computer-implemented method for manipulating data beingvisualized on a display. The method involves receiving visualizable datahaving been pre-processed according to the above-described method. Thevisualizable data thus represent a scene as seen from a specifiedposition. The scene includes at least one object to which a selectionmargin is assigned within which selection margin the at least one objectis validly selectable for manipulation in addition to an area of theobject shown towards a view thereof as seen from the specified position.The method further involves checking if user input has been obtained,which user input expresses manipulation of one of the at least oneobject in the area of the object shown towards the view thereof as seenfrom the position, or in the selection margin. If such user input isobtained, manipulation of the object is enabled based on the obtaineduser input. As a result, a user may interact with the object in areliable and consistent manner also if the object as such shows a smalland/or irregular area towards the view from the specified position.

Further advantages, beneficial features and applications of the presentinvention will be apparent from the following description and thedependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is now to be explained more closely by means of preferredembodiments, which are disclosed as examples, and with reference to theattached drawings.

FIG. 1 shows a schematic view of a scene with objects as seen from aspecified position;

FIG. 2 illustrates visualizable data representing the scene in FIG. 1,where a selection margin is assigned to one of the objects;

FIGS. 3-5 illustrate how the selection margin is assigned according toembodiments of the invention;

FIGS. 6a-c illustrate how an object is encapsulated by cuboid in orderto assign a selection margin to the object according to one embodimentof the invention; and

FIG. 7 shows a block diagram of a processing circuitry according to oneembodiment of the invention;

FIG. 8 illustrates, by means of a flow diagram, the general methodaccording to the invention for pre-processing visualizable data to bemanipulatable in response to user input.

DETAILED DESCRIPTION

FIG. 1 shows a schematic view of a scene S with objects 110, 120 and 130as seen from a specified position P, which is located at a givencoordinate in a three-dimensional (3D) coordinate system X, Y, Zrelative to the scene S. This means that each of the objects 110, 120and 130 shows a particular surface area towards a view direction V ofthe scene S as seen from the position P. If the position P changes;typically, the view direction V of the scene S also changes. As afurther result, the objects 110, 120 and 130 show respective surfaceareas towards the new view direction V of the scene S, which surfaceareas may be at least slightly different.

Depending on the angle of the view direction V, the shape of and/or thedimensions of an object, the object may show a very small area towardsthe position P. Consequently, it may be complicated for a user tomanipulate the object, for example via a gazed-based selectionoperation.

Therefore, according to the invention, the visualizable data D_(in) thatrepresent the scene S are pre-processed in at least one processor aswill be described below. The visualizable data Di_(n) describe the sceneS as seen from a position P, which may for example be given by thelocation of a virtual camera in a 3D graphics environment.

Inter alia, the pre-processing of the visualizable data D_(in) accordingto the invention aims at facilitating gaze-based selection operations inrespect of the objects 110, 120 and 130 in the scene S. The gaze-basedselection operations rely on gaze data registered for a subject whoregards a display on which the scene S is presented as seen from theposition P. Additionally, or alternatively, the proposed pre-processingof the visualizable data D_(in) facilitates tactile user input, which isregistered on a display presenting the scene S as seen from the positionP.

Referring now to FIG. 2, we will illustrate how a selection margin M isassigned to one object 110 in the scene S being represented by thevisualizable data D_(in).

A first measure L1 is determined, which first measure L1 represents anextension of the object 110 in a smallest dimension as seen from theposition P. Here, the first measure L1 is oriented parallel to a firstaxis X of the 3D coordinate system. A second measure L2 is determined,which second measure L2 represents an extension of the object 110 in alargest dimension as seen from the position P. The second measure L2 ishere oriented in parallel with a second axis Y of the 3D coordinatesystem. Of course, as will be discussed below, the first and secondmeasures L1 and L2 respectively may have any orientation relative to the3D coordinate system in which the object is located.

An object aspect ratio R is calculated based on the first and secondmeasures L1 and L2. The object aspect ratio R represents a relationshipbetween the first and second measures L1 and L2. In this example, theobject aspect ratio R is approximately 1:3 for the object 110.

Based on the object aspect ratio R, a selection margin M is assigned tothe object 110. The selection margin M designates a zone outside of theobject 110 within which zone the object 110 is validly selectable formanipulation in addition to an area A₁₁ of the object 110 shown towardsa view V thereof as seen from the position P. Here, the area A₁₁ is thesize of a planar projection of the object 110 in a plane perpendicularto a direction of the view V.

Preferably, the selection margin M is assigned such that the zone has awider extension z2 from a side extending in a general direction of thelargest dimension of the object 110 (i.e. along L2) than an extension z1of the zone from a side extending in a general direction of the shortestdimension of the object 110 (i.e. along L1) as seen from the position P.Such a selection margin M renders it easier for a user to select theobject 110 because also a near miss, however within the margin M,results in a valid selection of the object 110; and due to the objectaspect ratio R, the risk of missing the object 110 is higher near thesides of the object 110 that extend in its largest dimension than anyother sides of the object 110.

FIG. 3 illustrates how the selection margin M1, M2, M3, M4 and M5 isassigned according to embodiments of the invention. As can be seen, theselection margin is here assigned such that the zone has a widerextension from the object sides that extend in the general direction ofthe largest dimension of the object. Moreover, the extension of the zonevaries depending on the object aspect ratio R, so that for an objectaspect ratio R close to one there is a relatively small differencebetween the extension of the zone along the largest and smallestdimensions; and for an object aspect ratio R far from one, there is arelatively large difference between the extension of the zone along thelargest and smallest dimensions.

For example, in FIG. 3, a first object 310 has an object aspect ratio Rof 0.068. Here, a selection margin M1 has a widest extension of the zonecorresponding to a factor 1.4 times L1 outside of the sides extending inthe general direction of the largest dimension of the first object 310and a narrowest extension of the zone corresponding to a factor 0.80times L1 outside of the sides extending in the general direction of thesmallest dimension of the first object 310.

A second object 320 in FIG. 3 has an object aspect ratio R of 0.071.Here, a selection margin M2 has a widest extension of the zonecorresponding to a factor 1.2 times L1 outside of the sides extending inthe general direction of the largest dimension of the second object 320and a narrowest extension of the zone being zero outside of the sidesextending in the general direction of the smallest dimension of thesecond object 320.

A third object 330 in FIG. 3 has an object aspect ratio R of 0.45. Here,a selection margin M3 has a widest extension of the zone correspondingto a factor 0.20 times L1 outside of the sides extending in the generaldirection of the largest dimension of the third object 330 and anarrowest extension of the zone corresponding to a factor 0.10 times L1outside of the sides extending in the general direction of the smallestdimension of the third object 330.

A fourth object 340 in FIG. 3 has an object aspect ratio R of 0.68.Here, a selection margin M4 has a widest extension of the zonecorresponding to a factor 0.18 times L1 outside of the sides extendingin the general direction of the largest dimension of the fourth object340 and a narrowest extension of the zone corresponding to a factor 0.12times L1 outside of the sides extending in the general direction of thesmallest dimension of the forth object 340.

A fifth object 350 in FIG. 3 has an object aspect ratio R of 0.90. Here,a selection margin M5 has a widest extension of the zone correspondingto a factor 0.11 times L1 outside of the sides extending in the generaldirection of the largest dimension of the fifth object 350 and anarrowest extension of the zone corresponding to a factor 0.04 times L1outside of the sides extending in the general direction of the smallestdimension of the fifth object 350.

Thus, as can be seen in FIG. 3, the extension of the selection margin Mvaries with the object aspect ratio R in such a manner the selectionmargin M has a relatively small widest extension for objects with anobject aspect R close to one, and a relatively large widest extensionfor objects with object aspect ratios R comparatively far from one.According to one embodiment of the invention, this relationship isexpressed as E=KR^(−x).

E is here the extension of the zone in at least one direction outsidethe object. The extension E may be expressed in terms of a factor of theshortest extension L1, or in terms of an angle as will be discussedbelow with reference to FIG. 4. K is a constant larger than zero, forexample 1. R is the object aspect ratio, smaller ler than or equal toone, i.e. L1/L2, and x is a constant larger than or equal to one, forexample 1.

According to the invention, the selection margin M may be zero, i.e.non-existent, along one or more of an object's sides. However, theselection margin M always has a zone with a non-zero extension outsideat least one side of the object. For example, in FIG. 3, the secondobject 320, which has an object aspect ratio R of 0.071 (i.e.comparatively far from one) is assigned a selection margin M such thatthe zone has a non-zero extension outside of the second object 320 alonga respective buffer side B1 and B2 of the second object 320, whichbuffer sides extend along the second object's 320 largest dimension L2.

FIG. 4 illustrates how the selection margin M is assigned according toone embodiment of the invention, namely based on a threshold angle αoutside of at least one edge E2L and/or E2R of an object 110 in a view Vof the object 110 as seen from the position P. FIG. 4 shows aperspective top view of the object 110 in FIGS. 1 and 2. The selectionmargin M has an extension z2 outside of a left-hand side edge E2L of theobject 110. The selection margin M also extends an amount z2 outside ofa right-hand side edge E2R of the object 110. The extension z2 isdefined based on the threshold angle α outside of the left-hand andright-hand side edges E2L and E2R respectively in the view V of theobject 110 as seen from the position P. Thus, the selection margin Mcreates buffer sides extending along the object's 110 largest dimensionL2. Here, due to the object's 110 relatively small object aspect ratioR, the selection margin M only extends a minimal amount z1, for examplezero, outside the sides of the object 110 extending along the object'ssmallest dimension L1.

FIG. 5 illustrates how the first and second measures L1 and L2respectively are determined of according to one embodiment of theinvention, which first and second measures L1 and L2, in turn, serve asa basis for assigning the selection margin M51 to an object 510. Theprocedure involves the following steps. First, the object 510 isencapsulated in a rectilinear box 500 covering the object 510 in theview V thereof as seen from the position P. For example, the rectilinearbox 500 may cover the object 510 with minimal margin as illustrated inFIG. 5. Then, the first and second measures L1 and L2 are set equal to ashortest side and a longest side respectively of the rectilinear box500. In an alternative embodiment of the invention (not shown), therectilinear box does not fully encapsulate the object 510. Instead, inthis embodiment, the rectilinear box may be defined to haveapproximately the same volume as the object 510. Thus, in case of anirregular object 510 as illustrated in FIG. 5, the rectilinear box will,at least partially, “cut through” the object 510.

In practice, to determine the first and second measures L1 and L2 for anarbitrary object, it may be advantageous to apply the below method.FIGS. 6a to 6c illustrate how an object 610 is encapsulated by cuboid600 in order to assign a selection margin M6 to the object according toone embodiment of the invention.

The method involves the following steps.

First, position data are obtained, which position data describe arespective position of each of at least four corners C1, C2, C4, and C5of the cuboid 600 that encapsulates the object 610. The at least fourcorners include a base corner C1 and three corners of the cuboid 600,which three corners C2, C4 and C5 are located on a respective edge thatis directly connected to the base corner C1 and which corners arevisible from the position P in the view direction V. In the illustratedexample, each of the three corners C2, C4 and C5, is positioned in adirection, seen from the base corner C1, which direction is orthogonalto the other two directions.

Optionally, in a second step, based the at least four corners C1, C2, C4and C5, a respective position may be derived for each remaining cornerC3, C6 and C7 that is visible from the position P in the view directionV. In some cases, the position P is not known when determining thepositions of corners of the cuboid 600. Thus, also the corner C8 may bedetermined.

Third, each of said at least four visible corners C1, C2, C4 and C5 (andpossibly any other corner C3, C6 and/or C7 being visible from theposition P derived in the second step) is projected onto a plane that isorthogonal to a direction of the view V. Thus, a planar projection PPLof the cuboid 600 is obtained.

Fourth, a largest diagonal DL in the planar projection PPL isdetermined, which largest diagonal DL, in this example, extends betweenthe corners C1 and C3.

Fifth, a cross-measure CM is determined, which cross measure CM isperpendicular to the largest diagonal DL, and which cross measure CMextends between two opposing sides of the planar projection PPL.

Sixth, the first measure L1 is assigned equal to the cross-measure CM,and the second measure L2 is assigned equal to the largest diagonal DL.

Finally, the selection margin M6 is assigning, based on the objectaspect ratio R as described above.

FIG. 7 shows a block diagram of a processing circuitry 710 according toone embodiment of the invention. The processing circuitry 710 containsat least one processor 720. The at least one processor 720 iscommunicatively connected to a non-volatile data carrier 730, which mayeither be included in the processing circuitry 710, or be located in acomponent external thereto.

The non-volatile data carrier 730 stores a computer program product 735containing software configured to, when the computer program product 735is run on the at least one processing circuitry 720, cause the at leastone processing circuitry 720 to carry out the following steps:

-   -   obtain visualizable data D_(in) representing a scene S including        at least one object, which visualizable data D_(in) describe the        scene S as seen from a position P;    -   determine a first measure L1 representing an extension of the        object in a smallest dimension as seen from the position P;    -   determine a second measure L2 representing an extension of the        object in a largest dimension as seen from the position P;

calculate an object aspect ratio R representing a relationship betweenthe first and second measures L1 and L2; and

-   -   assign, based on the object aspect ratio R, a selection margin M        to the object, which selection margin designates a zone outside        of the object within which zone the object is validly selectable        for manipulation in addition to an area A₁₁ of the object shown        towards a view V thereof as seen from the position P.

In order to sum up, and with reference to the flow diagram in FIG. 8, wewill now describe the general method according to the invention forpre-processing visualizable data to be manipulatable in response to userinput, which method is performed in at least one processor.

In a first step 810 visualizable data are obtained, which visualizabledata represent a scene as seen from a position P. The scene includes atleast one object, for example defined in 3D graphics.

In a step 820 thereafter, a first measure is determined that representsan extension of the at least one object in the scene in a smallestdimension of the object as seen from the position. In step 820, a secondmeasure is also determined that represents an extension of the object ina largest dimension as seen from the position.

A subsequent step 830, calculates an object aspect ratio representing arelationship between the first and second measures, for example as aration between the first and second measures.

Then, in a step 840, a selection margin is assigned to the object basedon the object aspect ratio. The selection margin designates a zoneoutside of the object within which zone the object is validly selectablefor manipulation in addition to an area of the object shown towards aview thereof as seen from the position.

Thereafter, the procedure ends. Naturally, in practice, the procedure ispreferably repeated in respect of one or more other objects in thescene. Moreover, in response to a change in the scene and/or anadjustment of the position from which the scene is viewed, it isadvantageous to the repeated procedure, preferably with respect to eachobject in the scene.

All of the process steps, as well as any sub-sequence of steps,described with reference to FIG. 8 above may be controlled by means ofat least one programmed processor. Moreover, although the embodiments ofthe invention described above with reference to the drawings compriseprocessor and processes performed in at least one processor, theinvention thus also extends to computer programs, particularly computerprograms on or in a carrier, adapted for putting the invention intopractice. The program may be in the form of source code, object code, acode intermediate source and object code such as in partially compiledform, or in any other form suitable for use in the implementation of theprocess according to the invention. The program may either be a part ofan operating system, or be a separate application. The carrier may beany entity or device capable of carrying the program. For example, thecarrier may comprise a storage medium, such as a Flash memory, a ROM(Read Only Memory), for example a DVD (Digital Video/Versatile Disk), aCD (Compact Disc) or a semiconductor ROM, an EPROM (ErasableProgrammable Read-Only Memory), an EEPROM (Electrically ErasableProgrammable Read-Only Memory), or a magnetic recording medium, forexample a floppy disc or hard disc. Further, the carrier may be atransmissible carrier such as an electrical or optical signal which maybe conveyed via electrical or optical cable or by radio or by othermeans. When the program is embodied in a signal which may be conveyeddirectly by a cable or other device or means, the carrier may beconstituted by such cable or device or means. Alternatively, the carriermay be an integrated circuit in which the program is embedded, theintegrated circuit being adapted for performing, or for use in theperformance of, the relevant processes.

The term “comprises/comprising” when used in this specification is takento specify the presence of stated features, integers, steps orcomponents. However, the term does not preclude the presence or additionof one or more additional features, integers, steps or components orgroups thereof.

The invention is not restricted to the described embodiments in thefigures but may be varied freely within the scope of the claims.

The invention claimed is:
 1. A method performed in at least oneprocessor for pre-processing visualizable data to be manipulatable inresponse to user input, the method comprising the steps of: obtainingvisualizable data representing a scene including at least one object,the visualizable data describing the scene as seen from a position,determining a first measure representing an extension of the object in asmallest dimension, and a second measure representing an extension ofthe object in a largest dimension as seen from the position, calculatingan object aspect ratio representing a relationship between the first andsecond measures, and assigning, based on the object aspect ratio, aselection margin to the object, the selection margin designating a zoneoutside of the object within which zone the object is validly selectablefor manipulation in addition to an area of the object shown towards aview thereof as seen from the position.
 2. The method according to claim1, wherein the selection margin is assigned such that the zone has anon-zero extension outside of the object along at least one buffer sideof the object.
 3. The method according to claim 2, wherein each of theat least one buffer side is located on a side of the object, which sideextends in a general direction of the largest dimension of the object.4. The method according to claim 2, wherein the selection margin isassigned such that the zone has a wider extension from a side extendingin a general direction of the largest dimension of the object than anextension of the zone from a side extending in a general direction ofthe shortest dimension of the object as seen from the position.
 5. Themethod according to claim 1, wherein the selection margin is definedbased on a threshold angle outside of at least one edge of the object inthe view thereof as seen from the position.
 6. The method according toclaim 1, wherein, the selection margin is assigned such that anextension of the zone in at least one direction outside of the objectdepends on the object aspect ratio according to the expression:E=KR^(−x), where E is the extension of the zone in the at least onedirection, K is a constant larger than zero, R is the object aspectratio, smaller than or equal to one, and x is a constant larger than orequal to one.
 7. The method according to claim 1, wherein thedetermining of the first and second measures comprises the steps of:encapsulating the object in a rectilinear box covering the object in theview thereof as seen from the position, setting the first measure equalto a shortest side of the rectilinear box, and setting the secondmeasure equal to a longest side of the rectilinear box.
 8. The methodaccording to claim 1, wherein determining the first and second measurescomprises the steps of: obtaining position data describing a respectiveposition of each of at least four corners of a cuboid encapsulating theobject, projecting, based on the respective position of each of the atleast four corners, each of the eight corners being visible from theposition onto a plane that is orthogonal to a direction of the view,thus obtaining a planar projection of the cuboid, determining a largestdiagonal in the planar projection, determining a cross measure beingperpendicular to the largest diagonal, and which cross measure extendsbetween two opposing sides of the planar projection, assigning the firstmeasure equal to the cross measure, and assigning the second measureequal to the largest diagonal.
 9. The method according to claim 1,wherein the user input is produced based on at least one of: gaze dataregistered for a subject regarding a display on which the scene ispresented as seen from the position, and tactile input registered on adisplay presenting the scene as seen from the position.
 10. A computerprogram product loadable into a non-volatile data carriercommunicatively connected to at least one processor, the computerprogram product comprising software configured to, when the computerprogram product is run on the at least one processing circuitry, causethe at least one processing circuitry to: obtain visualizable datarepresenting a scene including at least one object, the visualizabledata describing the scene as seen from a position, determine a firstmeasure representing an extension of the object in a smallest dimension,and a second measure representing an extension of the object in alargest dimension as seen from the position, calculate an object aspectratio representing a relationship between the first and second measures,and assign, based on the object aspect ratio, a selection margin to theobject, the selection margin designating a zone outside of the objectwithin which zone the object is validly selectable for manipulation inaddition to an area of the object shown towards a view thereof as seenfrom the position.
 11. A non-volatile data carrier containing thecomputer program product of the claim
 10. 12. A processing circuitry forpre-processing visualizable data to be manipulatable in response to userinput, the processing circuitry being configured to: obtain visualizabledata representing a scene including at least one object, thevisualizable data describing the scene as seen from a position,determine a first measure representing an extension of the object in asmallest dimension, and a second measure representing an extension ofthe object in a largest dimension as seen from the position, calculatean object aspect ratio representing a relationship between the first andsecond measures, and assign, based on the object aspect ratio, aselection margin to the object, the selection margin designating a zoneoutside of the object within which zone the object is validly selectablefor manipulation in addition to an area of the object shown towards aview thereof as seen from the position.
 13. A computer-implementedmethod for manipulating data being visualized on a display, the methodcomprising the steps of: receiving visualizable data having beenpre-processed according to the method of any of the claim 1, thevisualizable data thus representing a scene as seen from specifiedposition, and the scene including at least one object to which aselection margin is assigned within which selection margin the at leastone object is validly selectable for manipulation in addition to an areaof the object shown towards a view thereof as seen from the specifiedposition, checking if user input has been obtained, which user inputexpresses manipulation of one of the at least one object: in the area ofthe object shown towards the view thereof as seen from the position, orin the selection margin, and if such user input is obtained enablingmanipulation of said object based on the obtained user input.